摘要
利用电位滴定法测定不同溶剂中生成的羧甲基纤维素（ＣＭＣ）完全酶降解和酸水解后的还原端基数，计算出反映ＣＭＣ一条分子链上取代基均一性的参数，如取代及未取代葡萄糖单元（ＡＧＵ）的长度、单取代及双取代百分数等；研究这些ＣＭＣ的酸解程度随时间的变化，考察溶剂种类对ＣＭＣ取代基分布的影响．结果表明：用二甲亚砜作溶剂，反应效果最好；二氧六环、丙酮、异丙醇及叔丁醇的效果也佳，生成的ＣＭＣ取代基分布较均匀，耐酸性较强；甲醇和乙醇中生成的ＣＭＣ取代基分布均一性很差．
The number of reducing end groups of carboxyynethylcellulose (CMC ) producedin different solvents was experimentally determined by potentiometry after total enzymolysis andacidolysis. The parameters representing the equipartition of substituents along a molecular chainof CMC, such as the length of the substituted or unsubstituted anhydroglucose units (AGU) andthe percentage of monosubstituted or disubstituted units, etc., were calculated. The change of thedegree of acldolysls in these CMC’ s with time is also studied. The effect of different solvents on the distrlbution of substltuents of the CMC is researched. It shows that the reaction result is th.best in dimethyl sylfoxide and also excellent in dioxane, acetone, i-propanol or t-butanol. The dis-tribution of substituents is more uniform, and the resistance to acid is stronger, and equlpartition of the CMC produced in methanol and ethanol is the worst.
出处
《天津大学学报》
CSCD
1995年第5期647-652,共6页
Journal of Tianjin University(Science and Technology)
关键词
羧甲基纤维素
取代基分布
葡萄糖单元
纤维素
carboxpoethylcellulose(CMC)
distribution of substituent
different solvents
anhy- drojocose unit(AGU)
